Compression-operated fuel injector for diesel engines



Feb. 13, 1951 H. 1. SMITH 2,541,443

COMPRESSION-OPERATED FUEL INJECTOR FOR DIESEL ENGINES Filed April 16, 1945 s Sheets-Sheet 1 Inventor Feb 13, 1951 H. E. SMITH 2,541,443

COMPRESSION-OPERATED FUEL INJECTOR FOR DIESEL ENGINES Filed April 16, 1945 3 Sheets-Sheet 2 Feb. 13, 1951 H. l. SMITH 2,541,443

COMPRESSION-OPERATED FUEL INJECTOR FOR DIESEL ENGINES Filed April 16, 1945 3 Sheets-Sheet 5 I it 19 2 0 I n ventar jig k Z frail/E, 6'1 36' B, 2mm

50 WW Em Patented Feb. 13, 1951 COMPRESSION- OPERATED FUEL INJECTOR FOR DIESEL ENGINES Hugh I. Smith, Vallejo, Calif.

Application April 16, 1945, Serial No. 588,460

4 Claims.

This invention relates to fuel injectors for Diesel engines, and more particularly to an automatic fuel injector which is operated by the compression within the cylinder of the engine.

The primary object of the invention is to introduce Diesel fuel into an engine cylinder at a predetermined point of its compression stroke, and. also to meter the amount of fuel so injected.

Another object of the invention is to increase the efficiency of Diesel engines by eliminating the cam shaft and cam mechanism ordinarily employed so as to divert the power commonly consumed in operating such mechanism into the main power output of the engine.

The above and other objects may be attained by employin this invention which embodies, among its features, a compression-actuated valve which carries a metering and fuel conducting piston, yielding means for normally holding the valve in closed position, but adapted to yield to open the valve when the engine piston reaches top center in its compression stroke, means for limiting the distance which the valve can open by which the volume of fuel injected may be governed, yielding means for controlling the time of opening of the valve with relation to the position of the engine piston relative to top center, and means for regulating the pressure of the last-named yielding means on the valve by which its time of operation may be controlled.

In the drawings Figure 1 is a side View partly in section of a fuel injector embodying the features of this in vention,

Figure 2 is a lon itudinal sectional view through a fragment of an engine cylinder showing this improved fuel injector attached thereto, the section being taken in a plane at right angles to the plane of Figure 1,

Figure 3 is a top plan view of a fuel injector embodying this invention,

Figure 4 is a horizontal sectional view taken on the line i% of Figure 2, and

Figure 5 is a horizontal sectional View taken on the line 55 of Figure 2.

Referring to the drawings in detail, my improved metering pump includes a body I0 formed with an axial bore H opening through its lower end and communicating adjacent the upper end with an axial bore E2 of reduced diameter. Extending transversely through the body I0 adjacent the upper end of the bore l I are transverse bores l3 and similar transverse bores of smaller diameters M are formed in the body at a point between the upper and lower ends of the bore H.

Tightly fitted in the lower end of the bore H is a bushing 55 having a flange l6 which seats against the top of the cylinder head ll of an internal combustion engine of the Diesel type. The bushing i5 is formed with an internal bore l8 for the reception of the valve mechanism to be more fully hereinafter described. Extending laterally from opposite sides of the body [9 are attaching flanges is which are pierced to receive cap screws 23 by means of which the device is attached to the cylinder head ll. Attached by cap screws 21 to the upper end of the body I0 is a high-pressure cylinder body 22 provided near its lower end with attaching flange 23 through which the cap screws 2! extend, as will be clearly seen upon reference to Figure 2. The lower end of the high-pressure cylinder body 22 projects into the bore I2 and its lower edge terminates flush with the upper end of the bore I l in the body If). The high-pressure cylinder body 22 is formed with an axial bore 24 which opens into an enlarged axial bore 25 forming a shoulder 26 intermediate the ends of the high pressure cylinder 22, the purpose of which will be more fully hereinafter described.

Fitted into the upper end of the bore 25 i a ball valve body Zl provided at its upper end with an internally screw-threaded socket 28 which opens into a passage 29 which is normally closed by a ball valve 30 held against its seat by a compression coil spring 3|, the lower end of which seats on the shoulder 28 previously described.

The fuel injecting valve previously referred to is designated generally by the numeral 33 and comprises a sleeve 3 having at one end a flange 35, the upper face of which is provided with a concentric recess for a purpose to be more fully hereinafter described. Extending axially through the sleeve 34 is an internal bore 35, the end of which remote from the flange 35 is flared outwardly to form a seat 37 for the cone shaped-end or head of a piston and valve to be more fully hereinafter described.

The piston and valve above referred to comprises a plunger 38 which is provided at one end with a conical head 39 for cooperation with the tapered valve seat 3'! previously mentioned while the opposite end of the plunger enters the bore 24 of the cylinder body 22 Formed intermediate the ends of the stem 38 on the exterior thereof are screw threads Gil upon which an adjusting nut 4i and a lock-nut 42 are threaded.

Surrounding the stem 38 between the lock-nut 4! and the annular recess in the upper surface of the flange 35 of valve 33 is a compression coil spring 43 which serves to normally .hold the valve head 39 yieldingly in contact with the seat 31. Surrounding the coil spring 43, the adjusting nut 4|, and lock-nut 42 is another compression coil spring 44, the lower end of which seats in the recess in the top of the flange 35, and supported on the upper end of the last-named coil spring is a collar 45.

Extending axially through the openings l3 adjacent the upper end of the body ii] are cam members designated generally 46, each of which comprises end disks 4? having projecting from their outer faces squared extensions 48, by means of which the disks may be rotated in the openings 13. Joining the inner faces of the disks are eccentrically disposed bars 49 which, as shown in Figure 1, are tangent with the peripheries of the disks so as to form, in effect, cranks which intersect the bore ill and serve as stops to limit the upward movement of the collar 45, it being obvious that as the disks are rotated in the apertures [3, the bars 49 will move in an are as suggested by the dotted lines in Figure 1. It will thus be seen that the tension of the outer spring 44 may be varied to regulate the timing of the operation of the valve 33.

Mounted for rotation in the bores M- are similar cam members 50, which like the cam members previously described, comprise a pair of spaced disks 5i carrying on their outer faces squared extensions 52 and joined by bars 53, which, as illustrated in Figure 5, intersect the bore II and seve as stops to limit the upward movement of the sleeve 34.

As shown in Figure 2, the bore within the plunger 38 terminates short of the head 39 of the valve stem and communicates with the exterior thereof through a transversely extending bore 54 to form a discharge passage for fluid displaced by the advance of the plunger 38 into the bore 24 of the cylinder body 22. That portion of the plunger between the upper end of the conical head 39 and the transverse bore 54 is relieved, as at 55, for a purpose to be more fully herinafter described.

In operation, the device is attached as shown to the cylinder head I! of an internal combustion engine of the Diesel type. The nut 4! is first adjusted so as to cause the inner spring 43 to exert a pressure on the top of the valve 33 substantially equal to the cylinder compression pressure acting on the valve with the upstroke of the engine piston P. Fuel being introduced into the device through the socket 28 which is connected to the fuel supply line is trapped in the bore 25 by the ball valve 3!] and will be forced downwardly through the discharge passage in the plunger 38 and discharged into the space formed by the relief 55 to force the head 39 against the effort of the spring 43 away from the seat 31. The fuel will thus be injected into the engine cylinder between the seat 3'! and the head 39. In order to regulate the timing and secure the most satisfactory operation of the engine, the cam members 46 are adjusted by rotating the disks 4'! in the transverse openings 43 so as to bring the bars 49 into the desired position to exert prop-er tension on the spring 44 and thus cause the valve 33 to be held downwardly under the yielding pressure of the spring 44. In this manner the exact timing of the operation of the valve can be regulated. In order to control the volume of fuel which'may be injected into the engine cylinder, the cam members 50 are next adjusted by rotating their disks 5i within their respective openings 14 so as'to bring the bar members 53 to a position to limit the upward movement of the valve 33, as suggested by the dotted lines in Figure 1, and hence regulate the length of the stroke of the plunger and its displacement of fuel in the bore 25. In this manner, the exact volume of fuel discharge through the passages may be readily regulated and accurate metering obtained.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction, combina tion and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

Having thus described the invention, what is claimed as new is:

l. A dispensing nozzle comprising a fluid confining cylinder, a plunger entering one end of the cylinder and adapted to advance thereinto to displace fluid confined in the cylinder, said plunger having a discharge passage opening at one end into the cylinder and at its opposite end through the side of the plunger at a point remote from the cylinder, a valve head on the remote end of the plunger, a longitudinally movable sleeve encircling the end of the plunger remote from the cylinder, said head and sleeve cooperating to form a valve through which fluid pass ing through the discharge passage is distributed, resilient means yieldingly retaining the plunger against sliding movement, yielding means holding the valve head in cooperation with the sleeve, means operable externally of the cylinder to regulate the tension of the resilient means on the valve head and adjustable means to regulate the magnitude of movement of the valve head against its resilient means.

2. A dispensing nozzle comprising a fluid confining cylinder, a plunger entering one end of the cylinder and adapted to advance thereinto to displace fluid confined in the cylinder, said plunger having a discharge passage opening at one end into the cylinder and at its other end through the side of the plunger at a point remote from the cylinder, a valve head on the remote end of the plunger, a longitudinally movable sleeve encircling the end of the plunger remote from the cylinder, said head and sleeve cooperating to form a valve through whi h fillld passing through the discharge passage is distributed, means yieldingly holding the sleeve against movement on the plunger and retaining the sleeve in cooperation with the head, resilient means limiting opening movement of the valve head from the sleeve, and eccentrically externally controlled means for adjusting the resillent means.

3. A dispensing nozzle comprising a housing, a fluid confining cylinder mounted in one end of the housing, a plunger disposed longitudinally in the housing and having one end entering into the cylinder for advancing thereinto to displace fluid confined in the cylinder, said plunger hav-- ing a discharge passage opening into the cylinder and at its other end through the side of the plunger at' a point remote from the cylinder, a valve head on the remote end of the plunger and disposed at the other end of the housing, a 1ongitudinally movable sleeve encircling the plunger remote from the cylinder and cooperatively seating on the head to form a valve through which fluid passing through the discharge passage is distributed, a member disposed in the housing, a spring disposed between the member and sleeve, an adjustable stop onthe plunger, yielding means mounted between the stop and sleeve, means .operable externally of the housing for adjusting :f

the spring, said last means including eccentrically; mounted adjusting members operable on the.

4. A dispensing nozzle comprising a. housing, a fluid confining cylinder mounted in one end of; the housing, a plunger disposed longitudinally 10 Number in the housing and having one end entering into the cylinder for advancing thereinto to displace fluid confined in the cylinder, said plunger having a discharge passage opening into the cylinder and at its other end through the side of the plunger at a point remote from the cylinder, a: valve head on the remote end of the plunger and disposed at the other end of the housing, a ion; gitudinally movable sleeve encircling the plunger remote from the cylinder and cooperatively seat; ing on the head to form a valve through which fluid passing through the discharge passage is distributed, a member disposed in the housing, a

spring disposed between the member and sleeve, an adjustable stop on the plunger, yielding means 2 means to limit the opening of the head from the sleeve.

HUGH I. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,411,143 Whaley Mar. 28, 1922 1,497,258 Beals June 10, 1924 1,749,975 GroiT Mar. 11, 1930 1,995,459 Olsen Mar. 26, 1935 2,052,459 Geiser .Aug. 25, 1936 2,135,925 Tuscher Nov. 8, 1938 2,190,051 Tuscher Feb. 13, 1940 2,197,944 Raven Apr, 23, 1940 2,203,669 Butler June 11, 1940 2,371,787 Ward Mar. 20, 1945 2,389,492 Edwards Nov. 20, 1945 FOREIGN PATENTS Number Country Date 8,714 Great Britain 1913 47,930 France Aug. 23, 1937 187,950 Great Britain Nov. 29, 1923 537,414 France May 23, 1922 

